A memorial to the last native Princess of Wales has been badly damaged by vandals.

The memorial to Princess Gwenllian was set up at Sempringham in Lincolnshire to mark the place where she was kept as a prisoner for 54 years following the death in battle of her father, Llywelyn ap Gruffudd, in 1282.

Gwenllian was the only heir of Llywelyn, the last native prince of Wales.

Edward the First of England, who completed the conquest of Wales with Llywelyn's death, made sure his Welsh opponent would have no descendents by having Gwenllian, a baby at the time of the conquest, kept a prisoner in a convent in Lincolnshire until her death 54 years later in 1337.

The memorial was erected at Sempringham nine years ago by Welsh people with the help of sympathetic locals.

Graffiti

But the slate inscription and heavy slate capping for the memorial stone - recently blessed by the Bishop of Bangor - have been smashed in the vandal attack. Graffiti has also been scratched on the plaque.

Mrs Mallt Anderson of Cardiff, who is secretary of the Princess Gwenllian Society which maintains Gwenllian's memory, said: "It is particularly sickening that this should have happened at a time when we are remembering the death of Diana, the last Princess of Wales of the new order.

"In addition to our many Welsh supporters, in recent times we have been grateful for the support of all our local Lincolnshire friends who have helped us so readily in our determination to maintain and care for this tiny corner of an English field that is forever Wales."

She said the society was determined that the memorial would be restored after the attack.